Brain impairment in people with HIV may not be as common as we thought

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Two studies presented at the17th British HIV Association
(BHIVA) conference last week suggest that the proportion of people who have
subtle brain impairment due to HIV may not be as high as previously thought,
and may in fact be little higher than in the general population.

Several studies measuring neurocognitive impairment
(deficits in memory, thinking and movement) in people with HIV in the last few
years have concluded that a high proportion of people with HIV have subtle
impairments. These may not cause symptoms that interfere with daily life, but
can be detected by psychological tests.

About 16% of the general population has some degree of
neurocognitive deficit. It therefore caused a lot of concern when in 2010 the large
CHARTER trial in the USA
found that 52% of 1526 people with HIV had evidence of neurocognitive
impairment.

A quarter of these people had other conditions that were
probably the major cause of their brain impairment, but that still meant that
39% of all HIV-positive patients had brain impairment without any other
obvious cause, and 36% of patients who had never had an HIV-related illness. Of
these 71%, or 28% of the entire group, had no obvious neurological symptoms.
CHARTER, therefore, suggested that HIV more than doubled the risk of brain
impairment in otherwise healthy people, raising concerns that it might become even
more common with age.

One study presented at BHIVA, however, found a rate of
asymptomatic neurocognitive impairment of only 19% in a group of patients with
suppressed viral loads, very little in excess of the general population rate.
Another study found that young people who had been born with HIV had rates of
neurocognitive impairment no higher than their HIV-negative siblings. This
study, and a third study that looked at rates of neurocognitive impairment in
the over-50s, found some evidence that some psychological tests that rely on
self-report might not be detecting actual difficulties in thinking and memory,
but rather people’s fear of them.

The St Mary’s Study

Dr Lucy Garvey from St Mary’s and Hammersmith
Hospitals in west London
reported on a survey (which won a prize for best presentation at the
conference) of 101 patients who were on stable antiretroviral therapy without
any obvious neurological symptoms or other illnesses. They had all had HIV for
more than six months.

The study subjects were given two types of psychological
test, a 20-minute computerised cognitive assessment test called Cogstate, and the International HIV
Dementia Scale (IHDS), a short, validated screening test for dementia employing
three simple memory and motor tasks.

Neurocognitive impairment was defined as scores more than
one standard deviation below the mean age-matched population data in at least
two areas of functioning – roughly within the lowest one-sixth of performance
scores.

The median age of the subjects was 53, and the majority (77%)
were white men. They had been HIV-positive for an average of 14 years, with a
mean CD4 count of 559 and lowest-ever CD4 count (nadir) of 185. A high
proportion – 25% – had hepatitis C, which is also associated with
neurocognitive disorders.

The overall rate of neurocognitive impairment was 19% in
this group, only 3% above the rate in the general population. The pattern of
domains affected was familiar from other studies of people with HIV, in that
fine muscular movement, multitasking and executive function (prioritising and
planning) were particularly impaired, and CD4 nadir was associated with a high
IHDS score, but nonetheless the impairments seen were slight.

“Many cohorts have reported HIV-associated neurological
disorder, but their antiretroviral therapy status and health have been widely
variable,” commented Dr Garvey. “This is one of the first studies to look at
neurocognitive impairment only in stable HIV-asymptomatic patients on
suppressive antiretroviral therapy.”

The St Mary’s team will now conduct further studies to look
at neurocognitive disorder in drug-naive patients with unsuppressed HIV.

Young people and brain impairment

The results from this study were echoed by another study
from St Mary’s that looked at neurocognitive function in young people who had
been born with HIV. It studied 31 young people aged 16-25 (mean age 20) and
compared their performance with 14 of their HIV-negative siblings. The two
groups were matched for age, ethnicity (both 85% black African) and gender (33%
and 29% respectively were male in the positive and negative groups). Seventy-nine
per cent of the positive subjects were on antiretrovirals of whom 70% were
virally suppressed (55% of the whole group).

These subjects were given the Cogstate computerised tests and the IHDS, and were also given the prospective
and retrospective memory scale (PRMQ) questionnaire, a self-reported rating of
problems with recall and retention of information. A minority of both groups
were also given an MRI brain scan to detect
signs of inflammation.

The positive and negative group had identical scores on the
IHDS and on the Cogstate test in all
domains. The PRMQ score was significantly worse (p=0.023) for the HIV-positive
young people, and there were also high levels of activity of certain
neurotransmitters in the basal ganglia area of the brain, a finding seen in
other studies.

However presenter Jane Ashby commented that the PRMQ
questionnaire, as a self-report, could measure subjects’ concern about memory
problems as much as actual ones, and so far no study in HIV has established whether the inflammation seen in MRI
scans is actually associated with neurocognitive performance.

Screening for brain impairment

The idea that some psychological tools might be reporting HIV-positive
people’s fears of dementia rather than actual impairment, and might over-report
neurological problems, has led London’s first dedicated HIV clinic for people
over 50, at the Chelsea and Westminster Hospital, to include two ten-minute
psychological questionnaires for generalised anxiety disorder and depression as
standard first steps in psychological assessment of patients, only proceeding
to tests for neurological function once these are eliminated.

The researchers comment that “high levels of anxiety,
depression and concern about cognitive function” are common in older patients
and that “memory loss, mental slowing and psychomotor disorder are common
manifestations of these conditions” and should therefore be assessed and
treated first.

NAM’s information is intended to support, rather than replace, consultation with a healthcare professional. Talk to your doctor or another member of your healthcare team for advice tailored to your situation.

The Community Consensus Statement is a joint initiative of AVAC, EATG, MSMGF, GNP+, HIV i-Base, the International HIV/AIDS Alliance, ITPC and NAM/aidsmap

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This content was checked for accuracy at the time it was written. It may have been superseded by more recent developments. NAM recommends
checking whether this is the most current information when making decisions that may affect your health.

NAM’s information is intended to support, rather than replace, consultation with a healthcare professional. Talk to your doctor or another member
of your healthcare team for advice tailored to your situation.